Variational Persistence of Periodic and Quasi-Periodic Orbits in Symmetric $N$-Body Problems
Many mechanical systems, such as the Newtonian $n$-body system, are invariant under rotations. The rotational symmetry of the system gives rise to two commuting actions: the dynamical action and the action of the symmetry group. In this paper, we exploit this symmetry to construct families of periodic and quasi-periodi...